Light emitting device

ABSTRACT

A light emitting device includes a substrate, a light emitting device and a sealing resin member. The substrate includes a flexible base, a plurality of wiring portions, a groove portion and a pair of terminal portions. The flexible base extends in a first direction corresponding to a longitudinal direction of the substrate and the plurality of wiring portions are arranged on the flexible base. The groove portion is formed between the plurality of wiring portions spaced apart from each other. The pair of terminal portions is arranged along the first direction at the both sides of the plurality of wiring portions. The light emitting element is disposed on the substrate and electrically connected to the plurality of wiring portions. The sealing resin member seals the light emitting element and a part of the substrate. The light emitting element is mounted on the substrate in a flip-chip manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/565,045 filed on Dec. 9, 2014, which is acontinuation application of U.S. patent application Ser. No. 13/936,399filed on Jul. 8, 2013, now U.S. Pat. No. 8,916,903. This applicationclaims priority to Japanese Patent Application No. 2012-153421, filed onJul. 9, 2012. The entire disclosures of U.S. patent application Ser.Nos. 13/936,399 and 14/565,045, and Japanese Patent Application No.2012-153421 are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting device.

2. Description of the Related Art

There has been proposed a light emitting device which includes a lightemitting element arranged on a flexible substrate, and a sealing memberwhich seals the light emitting element (see, for example, PatentLiterature 1: JP2005-322937 A). The light emitting device described inPatent Literature 1: JP2005-322937 A can be rolled up during theproduction process and transportation, and also can be cut in a desiredsize for use.

However, in the light emitting device described in JP2005-322937 A,there is a problem in that when the light emitting device is rolled up,concentrations of stress tend to be experienced between the sealingmember which seals the light emitting element and the substrate.

SUMMARY OF THE INVENTION

The light emitting device according to the various embodiments includesa substrate, a light emitting device and a sealing resin member. Thesubstrate includes a flexible base, a plurality of wiring portions, agroove portion and a pair of terminal portions. The flexible baseextends in a first direction corresponding to a longitudinal directionof the substrate and the plurality of wiring portions are arranged onthe flexible base. The groove portion is formed between the plurality ofwiring portions spaced apart from each other. The pair of terminalportions is arranged along the first direction at the both sides of theplurality of wiring portions. The light emitting element is disposed onthe substrate and electrically connected to the plurality of wiringportions. The sealing resin member seals the light emitting element anda part of the substrate. The light emitting element is mounted on thesubstrate in a flip-chip manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of a light emitting device according toa first embodiment.

FIG. 2 is an enlarged plan view near a light emitting element shown inFIG. 1.

FIG. 3 is a cross sectional view taken along line A-A of FIG. 2.

FIG. 4 is an enlarged view of FIG. 1.

FIG. 5 is a schematic plan view of a light emitting device according toa second embodiment.

FIG. 6 is a schematic plan view of a light emitting device according toa third embodiment.

FIG. 7 is an enlarged plan view of a groove portion.

DETAILED DESCRIPTION OF EMBODIMENTS

Next, embodiments will be described with reference to the drawings. Inthe description of the drawings below, the same or similar componentsare denoted by the same or similar reference symbols. However, it shouldbe noted that the drawings are drawn schematically, and the dimensionalratios and the like of the components may differ from the actual ratios.Accordingly, the specific dimension and the like should be determined inconsideration of the description below. It should be understood from thedrawings and the description herein, that the components of theembodiment shown in the drawings are not limited to the dimensionalrelationships depicted therebetween, but can be provided with differingrelative dimensions that those shown.

The present embodiment is devised in the light of such circumstances,and it is hence an object thereof to provide a light emitting device inwhich stress experienced between the sealing member which seals thelight emitting element and the substrate can be reduced.

1. First Embodiment

Structure of Light Emitting Device 100

A structure of a light emitting device 100 according to a firstembodiment will be described with reference to the drawings. FIG. 1 is aplan view showing a structure of a light emitting device 100. FIG. 2 isan enlarged plan view near a light emitting element 30 shown in FIG. 1.FIG. 3 is a cross sectional view taken along line A-A of FIG. 2.

The light emitting device 100 includes a substrate 10, a plurality ofsealing resin members 20, and a plurality of light emitting elements 30.The light emitting device 100 is flexible, so that it can be storedrolled-up on a reel etc., and can be installed along a curved surface.

The substrate 10 is a flexible elongated member. A first direction D₁,shown in FIG. 1, corresponds to the longitudinal direction of thesubstrate 10 and a second direction D2 is substantially perpendicular tothe first direction D₁ and corresponds to the lateral direction of thesubstrate 10. The ratio of the lengths of the substrate 10 in thelongitudinal direction and the lateral direction can be appropriatelyadjusted, for example, to be 6:1, 30:1, or 100:1. The length of thesubstrate 10 in the longitudinal direction can be 1150 mm, and thelength of the substrate 10 in the lateral direction can be 15 mm, forexample. The substrate 10 includes a flexible base 11, a plurality ofwiring portions 12, a pair of terminal portions 13, a groove portion 14,and a reflective layer 15.

The substrate 10 is made of a flexible insulating material. For such amaterial, an insulating resin such as polyethylene terephthalate andpolyimide can be preferably used but is not limited thereto. Forexample, the base 11 can be made of a strip of copper foil or aluminumfoil which is covered with an insulating resin. The base 11 can have athickness of about 10 μm to about 100 μm. The material of the base 11can be appropriately selected in view of the type of mounting of thelight emitting elements 30, the reflectance, adhesiveness with othermembers, etc. For example, in the case where a solder is used formounting the light emitting elements 30, a polyimide which has a highheat resistance can be preferably used, and in the case where thereflective layer 15, which will be described below, is not disposed onthe base 11, a material which has a high optical reflectance (forexample a white color material) can be preferably used.

The plurality of wiring portions 12 are arranged on a first main surfaceof the base 11. Each of the plurality of wiring portions 12 is made of athin metal film such as a copper foil or an aluminum foil, for example.Each of the plurality of wiring portions 12 can be formed with a crankshape as shown in FIG. 1. The plurality of wiring portions 12 can bearranged in a zigzag manner along the first direction D₁. The pluralityof wiring portions 12 are also arranged spaced apart from each other. Inthe present embodiment, the plurality of wiring portions 12 are coveredwith a reflective layer 15 and are connected to a corresponding lightemitting element 30 in a corresponding opening portion 151 to bedescribed below.

The wiring portions 12 have a thickness which does not impair theflexibility of the substrate 10 and a thickness of 8 μm to 150 μm ispreferable.

The wiring portions 12 are preferably arranged on the base 11 with thelargest possible area. With this arrangement, heat dissipation can beenhanced.

The corners of the wiring portions 12 are preferably rounded. Morespecifically, the radius of the rounded corners is preferably 100 μm orgreater.

A pair of terminal portions 13 can be arranged extending along the firstdirection D₁ on the main surface of the base 11. The pair of terminalportions 13 can be arranged along the second direction D₂ at the bothsides of each of the plurality of wiring portions 12. As in the presentembodiment, with the pair of terminal portions 13 extending along thefirst direction D₁ to the approximately entire sides of the base 11without being interrupted, the stress which is generated at the time ofbending the substrate 10 and is loaded on the light emitting elements 30and the sealing resin 20 can be reduced. A pair of external wirings 131are connected to the pair of terminal portions 13, respectively.Electric power is supplied through the pair of external wirings 131 tothe pair of terminal portions 13. The pair of external wirings 131 canbe connected to corresponding portions of known connectors (not shown)disposed on the base 11.

The pair of terminal portions 13 in addition to the wiring portions 12can increase the freedom of arrangement of the light emitting elements30. For example, it is possible that six light emitting elements 30 arearranged three in the first direction D₁ and two in the second directionD₂ as one block and connected in parallel, then, twelve blocks arearranged in the first direction D₁ and connected in series by a pair ofterminal portions 13. The pair of terminal portions 13 are at least madeup of a positive-side terminal portion 13 a and a negative-side terminalportion 13 b, and the number of the terminals of each of the pair ofterminal portions 13 is not specifically limited. Therefore, each of thepair of terminal portions 13 can be made up of a single terminal or canbe made up of a plurality of terminals.

The groove portion 14 is portion on the base 11 where the plurality ofwiring portions 12 and the pair of terminal portions 13 are notarranged. That is, the groove portion 14 is arranged between theplurality of wiring portions 12 which are spaced apart from each other,and between the wiring portions 12 and their corresponding terminalportions 13. In other words, the groove portion 14 separates the variouswiring portions 12 from one another. Further, as shown in the grooveportion 149,141′,142′,143′ for example, the groove portion 14 separatethe terminal portions 13 from one another and separate the terminalportions 13 from adjacent ones of the wiring portions 12. Hence, thegroove portion 14 is arranged between the pair of terminal portions 13which are spaced apart from each other. A part of the groove portion 14can be formed in a crank shape in top view, as shown in FIG. 1. Theinterval within the groove portion 14 is preferably narrower than thewidth of the wiring portions 12, and, for example, can be about 0.05 mmto about 5 mm. The configuration of the groove portion 14 will bedescribed later.

The reflective layer 15 covers the base 11, the plurality of wiringportions 12, the pair of terminal portions 13, and the groove portion14. The reflective layer 15 can cover approximately the entire uppersurface of the substrate 10 except for the opening portions 151 whichare described below. The reflective layer 15 is made of a material whichreflects the emission from the plurality of light emitting elements 30and the light whose wavelength is converted by a wavelength convertingmember which will be described later. For such a material, an insulatingwhite ink which is a so-called white resist made of a silicone resincontaining titanium oxide is preferably used but is not limited thereto.The reflective layer 15 includes a plurality of opening portions 151, asshown in FIG. 2 and FIG. 3. The opening portions 151 are arranged sothat the light emitting elements 30 are connected to the two wiringportions 12 or to a wiring portion 12 and a terminal portion 13,respectively.

The plurality of sealing resin members 20 are arranged on the substrate10 to cover the opening portions 151 of the reflective layer 15. In thepresent embodiment, the plurality of sealing resin members 20 arearranged in a row along the first direction D₁. Each of the sealingresin members 20 seals one light emitting element 30. In the presentembodiment, the sealing resin members 20 respectively have a hemisphereshape with the light emitting element 30 at the center, but the shape isnot limited thereto. Such sealing resin members 20 are made of alight-transmissive resin (an epoxy resin, a urea resin, a siliconeresin, etc). The sealing resin members 20 can contain a light diffusingagent (barium sulfate, titanium oxide, aluminum oxide, silicon oxide,etc). Also, the sealing resin members 20 preferably contain a wavelengthconverting member such as a fluorescent material which absorbs lightfrom the light emitting element 30 and release light with a differentwavelength than that of the absorbed light. Examples of such awavelength converting member include an oxide-based fluorescentmaterial, a sulfide-based fluorescent material, and a nitride-basedfluorescent material. For example, a gallium nitride based lightemitting element to emit blue light is used as the light emittingelement and fluorescent materials to absorb blue light, such as aYAG-based fluorescent material or a LAG-based fluorescent material toemit yellow to green light, a SiAlON-based fluorescent material to emitgreen light, and a SCASN-based fluorescent material and a CASN-basedfluorescent material to emit red light, are preferably used singly or incombination. Particularly, for the light emitting devices used for thedisplay devices such as backlights of liquid crystal displays andTV-screens, a SiAlON fluorescent material and a SCASN fluorescentmaterial are preferably used in combination. Also, for lightingapplications, a YAG-based fluorescent material or a LAG-basedfluorescent material and a SCASN-based fluorescent material or aCASN-based fluorescent material are preferably used in combination.

On the substrate 10, the plurality of light emitting elements 30 arearranged respectively in the opening portions 151 of the reflectivelayer 15. That is, the plurality of light emitting elements 30 arerespectively arranged spaced apart from the first groove portions whichextend in the second direction D₂ which intersects the first directionD₁. With this arrangement, detachment of the plurality of light emittingelements 30 from the substrate 10 can be prevented. In the presentembodiment, the plurality of light emitting elements 30 are arranged ina row along the first direction D₁. The two light emitting elements 30arranged at the center of the row are respectively connected to thewiring portion 12 and the terminal portion 13. Other light emittingelements 30 are respectively connected to two wiring portions 12. In thepresent embodiment, the light emitting elements 30 are mounted on thesubstrate 10 in a flip-chip manner so that the longitudinal direction ofeach light emitting element 30 is substantially in parallel to thesecond direction D₂. In detail, the light emitting elements 30respectively include a semiconductor structure 31, a p-side electrode32, an n-side electrode 33, and an insulating layer 24, as shown in FIG.3. The semiconductor structure 31 includes an n-type layer, an activelayer, and a p-type layer respectively made of a gallium nitride-basedsemiconductor and stacked in the order on a light-transmissive sapphiresubstrate. The n-side electrode 33 is disposed extending to a lowerportion of the p-type layer via the insulating layer 34. The p-sideelectrode 32 and the n-side electrode 33 are respectively connected to apair of wiring portions 12 via a pair of bonding members 35. For thebonding member, a solder such as a Sn—Ag—Cu based solder and an Au—Snbased solder, or a metal bump such as Au is preferably used. Anunderfill material 36 is applied between the light emitting element 30and the substrate 10. The underfill material 36 can be made of asilicone resin or an epoxy resin, for example. The underfill material 36preferably has a light reflecting property and more specificallycontains titanium oxide or silicon oxide which has a white color. Suchan underfill material 36 is preferably disposed on the groove portion14, on the plurality of wiring portions 12, and further on thereflective layer 15, as shown in FIG. 2 and FIG. 3. With thisarrangement, the light extracting efficiency can be enhanced and alsothe portions where the light emitting elements 30 are disposed can bereinforced efficiently.

Mounting of the light emitting elements 30 is not limited to a flip-chipmounting and a die-bonding or a wire bonding can be employed forbonding.

Configuration of Groove Portion 14

Next, the configuration of the groove portion 14 will be described withreference to the drawings. FIG. 4 shows a partially enlarged view ofFIG. 1.

The groove portion 14 includes at least one first groove portion 141, atleast one second groove portion 142, and at least one third grooveportion 143.

The first groove portion 141 extends in a direction whichperpendicularly intersects the first direction D₁ which is thelongitudinal direction of the substrate. In the present embodiment, thefirst groove portion 141 extends in the second direction D₂ which is alateral direction of the substrate. The length 141S of the first grooveportion 141 is about a fourth of the width 10S of the substrate 10 inthe second direction D₂.

The second groove portion 142 extends along the direction intersectingwith the first direction D₁ which is the longitudinal direction. In thepresent embodiment, in a similar manner as in the first groove portion141, the second groove portion 142 extends in the second direction D₂which is a lateral direction of the substrate. Thus, the first grooveportion 141 and the second groove portion 142 are formed approximatelyin parallel with each other. Also, the first groove portions 141 and thesecond groove portions 142 are arranged at different locations in thefirst direction D₁. That is, the first groove portions 141 and thesecond groove portions 142 are not formed along a single straight linein the second direction D₂. Also, the first groove portions 141 and thesecond groove portions 142 are formed at different locations in thesecond direction D₂. The length 142S of the second groove portions 142is, in a similar manner as in the first groove portions 141, about afourth of the width 10S of the substrate 10 in the second direction D₂.

A third groove portion 143 is continuous with at least one first grooveportion 141 and at least one second groove portion 142. The third grooveportion 143 extends along a direction which intersects the first grooveportion 141 and the second groove portion 142. In the presentembodiment, the third groove portions 143 extend along the firstdirection D₁ which is the longitudinal direction of the substrate. Thus,the third groove portions 143 are substantially perpendicularlyintersect the first groove portions 141 and the second groove portions142 respectively. The length 143S of the third groove portions 143 isgreater than the length 141S of the first groove portions 141 and thelength 142S of the second groove portions 142, but is not limitedthereto. At least one light emitting element 30 can be disposed over thethird groove portion 143. A sealing resin member 20 which seals thelight emitting element 30 is arranged over each of the third grooveportions 143.

The first groove portions 141 and the third groove portions 143 arerespectively connected to each other with a curve and the second grooveportions 142 and the third groove portions 143 are respectivelyconnected to each other with a curve. This arrangement allows smoothconnection between the first groove portions 141 and the third grooveportions 143 and between the second grooves 142 and the third grooves143. As described above, a plurality of groove portions are smoothlyconnected with a curve, which enables to prevent or reduce the stressconcentration in the regions where the plurality of groove portions areconnected one another. Accordingly, damage on the groove portion 14 andthe wiring portions 12 due to bending of the substrate 10 can beprevented.

In the present embodiment, the first groove portions 141 are spacedapart from each of the corresponding sealing resin member 20 and lightemitting element 30. In a similar manner, the second groove portions 142are spaced apart from each of the corresponding sealing resin member 20and light emitting element 30. That is, in the first direction D₁, thesealing resin member 20 and the light emitting element 30 are locatedbetween one of the first groove portions 141 and the correspondingsecond groove portion 142. Thus, the locations of the first grooveportions 141 in the first direction D₁ are different from the locationsof the sealing resin members 20 and the light emitting elements 30 inthe first direction D₁. In a similar manner, the locations of the secondgroove portions 142 in the first direction are D₁ different from thelocations of the sealing resin members 20 and the light emittingelements 30 in the first direction D₁. More specifically, in the firstdirection D₁, the second groove portions 142 and the sealing resinmembers 20 are preferably spaced from each other at a distance of 0.5 mmor more.

The locations of the first groove portions 141 in the second directionD₂ differ from the locations of the second groove portions 142 in thesecond direction D₂, however, the substrate 10 tends to bend at thefirst groove portions 141 and the second groove portions 142. On theother hand, the substrate 10 has a longer side in the longitudinaldirection, so that the substrate 10 is not likely bend at the thirdgroove portions 143 which are formed along the longitudinal direction.

The light emitting device 100 as described above employs the flexiblesubstrate 10, so that a roll-to-roll processing method can be used formanufacturing.

Performance and Effect

In the light emitting device 100 according to a first embodiment, thesealing resin 20 is disposed spaced apart from a plurality of firstgroove portions 141 of the groove portion 14 and extend in a seconddirection D₂ which intersects the first direction D₁.

As described above, the sealing resin members 20 are respectively spacedapart from the first groove portions 141. Thus, in the case where thesubstrate 10 is bent along the first groove portions 141, the bendingforce of the substrate 10 loaded on the connecting portions with thesealing resin members 20 can be reduced. In other words, arranging thesubstrate 10 so as to be easily bent along the first groove portions 141which are respectively spaced apart from the corresponding sealing resinmembers 20 allows reduction of a stress loaded on the connectingportions between the substrate 10 and the sealing resin members 20.Thus, detachment of the sealing resin members 20 from the substrate 10can be prevented.

The locations of the second groove portions 142 in the first directionare different from the locations of the sealing resin members 20 and thelight emitting elements 30 in the first direction D₁.

Thus, the bending force of the substrate 10 can be further preventedfrom loading on the connecting portions with the sealing resin members20.

The sealing resin members 20 are arranged over the third groove portions143 respectively.

Thus, the sealing resin members 20 are respectively spaced apart fromthe first groove portions 141 and the second groove portions 142, sothat the bending force of the substrate 10 loaded on the connectingportions with the sealing resin members 20 can be reduced.

2. Second Embodiment

Next, a structure of a light emitting device 100A according to a secondembodiment will be described with reference to the drawings. Thedifference of the second embodiment from the first embodiment is thatfive light emitting elements 30 are connected to a pair of wiringportions 12. Now, this difference will be mainly described below.

FIG. 5 is a partially enlarged plan view showing a configuration of alight emitting device 100A. As shown in FIG. 5, the light emittingdevice 100A can have a configuration in which a plurality of basicpatterns are connected in a longitudinal direction of the light emittingdevice 100A, in which each basic pattern can include a first and secondwiring portions 121, 122, a groove portion 14A, five sealing resinmembers 20, and five light emitting elements 30.

The first and second wiring portions 121, 122 are adjacent to each othervia the groove portion 14A. In a plan view, the first wiring portion 121can include four first protruded portions 121 a and five recessedportions 121 b. The four first protruded portions 121 a are protrudedtoward the second wiring portion 122 side. The five first recessedportions 121 b are respectively formed the both sides of each of thefour first protruded portions 121 a.

Also, in a plan view, the second wiring portion 122 can include fivesecond protruded portions 122 a and four second recessed portions 122 b.The five second protruded portions 122 a are protruded toward the firstwiring portion 121 side. The four second recessed portions 122 b arerespectively formed the both sides of each of the five second protrudedportions 122 a. The four first protruded portions 121 a are respectivelyprotruded into the four second recessed portion 122 b in an alternatemanner and the five second protruded portions 122 a are respectivelyprotruded into the five second protruded portions 121 b in an alternatemanner.

The groove portion 14A can include a first groove portion 141, a secondgroove portion 142, five third groove portions 143, four fourth grooveportions 144, and eight fifth groove portions 145.

The configuration of the first to the third grove portions 141 to 143 issimilar to that in the first embodiment.

The four fourth groove portions 144 are arranged at locations differentfrom that of the five third groove portions 143 in the second directionD₂. The four fourth groove portions 144 are arranged respectivelybetween the five third groove portions 143 in the first direction D₁. Inthe present embodiment, the four fourth groove portions 144 respectivelyextend along the first direction D₁ to be approximately in parallel tothe five third groove portions 143.

The eight five groove portions 145 are respectively connected to thethird groove portion 143 and the fourth groove portion 144. That is, thethird grove portions 143 and the fourth groove portions 144 areconnected via the fifth groove portions 145 respectively. In the presentembodiment, the fifth groove portions 145 extend along the seconddirection D₂ and approximately in parallel to the first groove portions141 and the second groove portions 142 respectively.

In the light emitting device 100A as described above, the sealing resinmembers 20 are also spaced apart from the first groove portions 141 andthe second groove portions 142 of each groove portion 14A. Thus,detachment of the sealing resin members 20 from the substrate 10 can beprevented.

3. Third Embodiment

Next, a structure of a light emitting device 100B according to a thirdembodiment will be described with reference to the drawings. The thirdembodiment differs from the first embodiment in that the shape of thegroove portion 14 is different, three or more terminal portions 13 areprovided, and two sealing resin members 20 each seals at least one lightemitting element 30 are spaced out on each hypothetical line in thesecond direction D₂. Now, mainly the differences will be describedbelow.

FIG. 6 is a partially enlarged plan view showing a configuration of alight emitting device 100B. As shown in FIG. 6, the light emittingdevice 100B can include a plurality of unit patterns, each of whichincludes: a third to a sixth wiring portions 123 to 126, a grooveportion 14B, and a groove portion 14C. In FIG. 6, a part of the lightemitting device 100B is shown enlarged, and in the light emitting device100B, the pattern shown in FIG. 6 is arranged repeatedly in thelongitudinal direction.

Each groove portion 14B is formed between the third wiring portion 123and the fourth wiring portion 124. Each groove portion 14C is formedbetween the fifth wiring portion 125 and the sixth wiring portion 126.Each of the groove portions 14B and the groove portions 14C can includea sixth groove portion 146, a seventh groove portion 147, and a eighthgroove portion 148.

The sixth groove portions 146 respectively extend along a directionwhich intersects the first direction D₁. In the present embodiment, eachsixth groove portion 146 extends along the second direction D₂ which isa lateral direction of the substrate.

The seventh groove portions 147 extend along a direction whichperpendicularly intersects the first direction D₁. In the presentembodiment, each seventh groove portion 147 extends along the seconddirection D₂ which is a lateral direction of the substrate. Also, thesixth groove portions 146 and the seventh groove portions 147 arearranged at different locations in the first direction D₁. Meanwhile,the sixth groove portions 146 and the seventh groove portions 147 whichare adjacent each other are arranged on the same locations in the seconddirection D₂.

The eights groove portions 148 are continuous with the sixth grooveportions 146 and the seventh groove portions 147 respectively. Theeighth grooves 148 extend along a direction which intersects the sixthgroove portions 146 and the seventh groove portions 147. In the presentembodiment, the eighth groove portions 148 extend along the firstdirection D₁ which is the longitudinal direction of the substrate. Theeighth groove portions 148 are substantially perpendicularly intersectthe sixth groove portions 146 and the seventh groove portions 147. Thelight emitting elements 30 re disposed over the eighth groove portions148 respectively. The sealing resin members 20 which seal the lightemitting elements 30 are disposed over the eighth groove portions 148respectively.

In the light emitting device 100B as described above, the sealing resinmembers 20 are also spaced apart from the sixth groove portions 146 andthe seventh groove portions 147 of each of the groove portions 14B and14B. Thus, detachment of the sealing resin members 20 from the substrate10 can be prevented.

Other Embodiments

The present embodiment is described with reference to the embodimentsillustrated in the accompanying drawings. It should be understood,however, that the description and the drawings are intended asillustrative of the present embodiment, and the scope of the presentembodiment is not limited to those described above. Various alternateembodiments, examples, and operational technologies will become apparentto one skilled in the art, from the description provided herein.

In the embodiments described above, the sealing resin members 20 and thelight emitting elements 30 are arranged on a main surface which is at aside of the substrate 10, but the arrangement is not limited thereto.The sealing resin members 20 and the light emitting elements 30 can alsobe arranged on the main surface and the opposite surface of thesubstrate 10.

In the above embodiments, each of the light emitting elements 30 isconnected to two wiring portions 12, but is not limited thereto. Each ofthe light emitting elements 30 can be connected to three wiring portions12. Also, each of the sealing resin members 20 is arranged on the twowiring portions 12, but can be arranged on three wiring portions 12.

In the above embodiments, all the wiring portions 12 are provided withat least one sealing member 20 and at least one light emitting element30, but are not limited thereto. The light emitting element 30 or/andthe sealing member 20 can be not disposed on some of the wiring portions12.

In the above embodiments, the substrate 10 includes three or more wiringportions 12, but at least two wiring portions 12 are sufficient to beprovided. Thus, the light emitting device 100 includes at least onesealing resin member 20 and one light emitting element 30.

In the above embodiments, a pair of (two) wiring portions 12 areconnected to one light emitting element 30, but a pair of wiringportions 12 can be connected to a plurality of light emitting elements30. Also, at least one light emitting element 30 can be connected to apair of terminal portions 13.

In the above embodiments, one sealing member 20 seals one light emittingelement 30, but one sealing member 20 can seal a plurality of lightemitting element 30.

In the above embodiments, in a plan view, the shape of the wiringportion 12 is respectively illustrated in FIG. 2, and FIG. 4 throughFIG. 6, but the shape of the wiring portion 12 is not limited thereto.The shape of the wiring portion 12 in a plan view can be changedappropriately according to the size of the substrate 10 and to thenumber of the light emitting element 30 to be used.

In the above embodiments, the groove portion 14 includes groove portionswhich extend in the second direction D2 (for example, the first andsecond groove portions 141, 142), but is not limited thereto. The grooveportion 14 includes at least a groove portion which extends in adirection intersects the first direction D₁.

In the above embodiments, the groove portion 14 is made up of aplurality of straight groove portions, but is not limited thereto. Atleast one of the plurality of groove portions can be formed with acurved shape, a wavy shape, or the like.

Although not shown in the above embodiments, in addition to the membersdescribed above, an associated member such as a Zener diode can bedisposed on the substrate 10 or on the wiring portions 12. Stress loadedbetween the associated members and the substrate 10 can be reduced byarranging the locations of the associated members with respect to thewiring portions 12 and the groove portion 14 in a similar manner as inthe light emitting elements 30.

In the above first embodiment, the substrate 10 includes a pair ofterminal portions 13, but is not limited thereto. For example, thesubstrate 10 includes twelve blocks of the light emitting elements 30and twelve pairs of terminals 13, in which, six light emitting elements30 are arranged three in the first direction D₁ and two in the seconddirection D₂ and are electrically connected as one block, then, twelveblocks are lined in the first direction D₁, and twelve pairs ofterminals 13 are respectively connected to the respective portions ofthe twelve blocks. Such a connection allows dimming operation to beperformed in the case where the light emitting device 100 is used forthe backlight of a TV-display, for example.

Although not shown in the above embodiments, at portions formed in aT-shape among the groove portion 14, the base 11 can be greatly bentalong the corresponding groove portions, which can result in a damage ofthe substrate 10 by the corners of a plurality of plurality of wiringportions. Thus, allowing the base 11 to bend in a multiple directionswill be advantageous.

For example, as shown in FIG. 7 which shows an enlarged view of thegroove portion 14, the substrate 10 can include the first to thirdwiring portions 201 to 203, and at least one first straight grooveportion 301 and at least one second straight groove portion 302. Thefirst wiring portion 201 is adjacent to the second and the third wiringportions 202, 203, respectively. The second and the third wiringportions 202, 203 are adjacent to each other. The first straight grooveportion 301 is arranged in a straight line between the first wiringportion 201 and the second and the third wiring portions 202, 203respectively. The second straight groove portion 302 is arranged in astraight line between the second wiring portion 202 and the third wiringportion 203. Also, the second straight groove portion 302 is arrangedsubstantially perpendicular to the first straight groove portion 301.Thus, the first straight groove portions 301 and the second straightgroove portions 302 intersect each other in a T-shape.

In a plan view, the first wiring portion 201 further includes aprojection 201A protruding in the first straight groove portion 301toward the second straight groove portion 302. In the example shown inFIG. 7, the planar shape of the protruded portion 201A is approximatelysemicircular, but other appropriate shapes such as triangular ortrapezoidal shape can also be employed. As described above, at theregion where the first straight groove portion 301 and the secondstraight groove 302 intersect, the groove becomes a Y-shape by theprojection 201A. With this arrangement, the base 11 can be preventedfrom bending sharply along the first straight groove portion 301 or thesecond straight groove portion 302.

Also, as shown in FIG. 7, the smallest distance Wminl between theprojection 201A and the second wiring portion 202 and the width W1 ofthe first straight groove portion 301 are approximately the same. Thesmallest distance Wmin2 between the projection 201A and the third wiringportion 203 and the width W1 of the first straight groove portion 301are approximately the same. The smallest distance Wminl and the smallestdistance Wmin2 are approximately the same. As described above, theprojection 201A allows the width of the grooves between the first tothird wiring portions 201 to 203 to be approximately the same or toreduce the difference of the width thereof, which can prevent the base11 from bending sharply.

Also, it is preferable that the width W1 of the second straight grooveportion 302 is wider toward the projection 201A. Thus, the walls of theboth sides of the second straight groove portion 302 are formed withcurved surfaces so that the second straight groove portion 302 can besmoothly connected to the first straight groove portion 301.

In the configurations described above, the groove portions are arrangedbetween a plurality of wiring portions respectively, but the grooveportions can be formed between one of the pair of terminal portions andone or more wiring portions.

As described above, it should be obvious that various other embodimentsare possible without departing the spirit and scope of the presentembodiments. Accordingly, the scope and spirit of the present embodimentshould be limited only by the following claims.

What is claimed is:
 1. A light emitting device comprising: a substrateincluding a flexible base extending in a first direction correspondingto a longitudinal direction of the substrate, a plurality of wiringportions arranged on the flexible base, a groove portion formed betweenthe plurality of wiring portions spaced apart from each other, and apair of terminal portions arranged along the first direction at the bothsides of the plurality of wiring portions respectively; a light emittingelement disposed on the substrate and electrically connected to theplurality of wiring portions, the light emitting element being mountedon the substrate in a flip-chip manner; and a sealing resin membersealing the light emitting element and the substrate.
 2. The lightemitting device according to claim 1, wherein the light emitting elementis spaced apart from a first groove portion of the groove portion, thefirst groove portion extending in a second direction intersecting thefirst direction.
 3. The light emitting device according to claim 2,wherein the light emitting element and the first groove portion arearranged along the first direction at different locations.
 4. The lightemitting device according to claim 2, wherein the groove portionincludes the first groove portion, a second groove portion extending inthe second direction, and a third groove portion connecting the firstgroove portion and the second groove portion, and the light emittingelement is disposed over the third groove portion.
 5. The light emittingdevice according to claim 4, wherein the first groove portion and thesecond groove portion provide more bending flexibility in the seconddirection than bending flexibility at the third groove portion.
 6. Thelight emitting device according to claim 2, wherein the sealing resinmember is spaced apart from the first groove portion of the grooveportion.
 7. The light emitting device according to claim 1, wherein thesubstrate includes a reflective layer arranged on the plurality ofwiring portions, the reflective layer includes an opening portion inwhich the light emitting element is arranged, the sealing resin membercovers the opening portion.
 8. The light emitting device according toclaim 7, wherein the flexible base is made of polyimide, and thereflective layer is made of silicone resin.
 9. The light emitting deviceaccording to claim 1, wherein a longitudinal direction of the lightemitting element is substantially in parallel to a second directionintersecting the first direction.
 10. The light emitting deviceaccording to claim 1, further comprising an underfill material appliedbetween the light emitting element and the substrate.
 11. The lightemitting device according to claim 7, further comprising an underfillmaterial disposed on the groove portion, on the plurality of wiringportions, and on the reflective layer.
 12. The light emitting deviceaccording to claim 10, wherein the underfill material has a lightreflecting property.
 13. The light emitting device according to claim 1,wherein a corner of at least one of the plurality of wiring portions isrounded.
 14. The light emitting device according to claim 1, wherein theflexible base has a thickness of 10 μm to 100 μm, and each of theplurality of wiring portions has a thickness of 8 μm to 150 μm.
 15. Thelight emitting device according to claim 1, wherein the sealing resinmember contains a wavelength converting member.
 16. The light emittingdevice according to claim 1, wherein the plurality of wiring portionshas a first wiring portion, a second wiring portion and a third wiringportion, the first wiring portion is adjacent to the second wiringportion and the third wiring portion, the second wiring portion and thethird wiring portion are adjacent to each other, two groove portions areformed between the first wiring portion, the second wiring portion andthe third wiring portion, and the first wiring portion includes aprotruded portion which is protruded toward the two groove portions at aregion where the two groove portions intersect.
 17. The light emittingdevice according to claim 1 further comprising a plurality of blockslined in the first direction, each of the plurality of blocks having aplurality of light emitting elements including the light emittingelement, wherein the plurality of light emitting elements areelectrically connected as each of the plurality of blocks, and the pairof terminal portions are respectively connected to each of the pluralityof blocks.
 18. The light emitting device according to wherein 1: each ofthe plurality of wiring portions is formed with a crank shape.
 19. Thelight emitting device according to claim 1, wherein the light emittingelement is connected to one of the pair of terminal portions and one ofthe plurality of wiring portions.
 20. The light emitting deviceaccording to claim 1, wherein the light emitting element has a sapphiresubstrate and a gallium nitride-based semiconductor.